With certain buildings, for example power stations, radio and television stations, pylons for high-voltage lines, military installations or the like, there exists today an increasing danger of acts of terror for political reasons. Hitherto known protective devices for such installations have included relatively high barbed-wire fences or concrete walls, erected at relatively great distances of, for example, about 100 m from the outer wall of the endangered building or construction. However, these obstacles can be overcome relatively quickly by terrorists with special tools, especially by blowing them up, so that the time for alerting the police and their arrival at the scene of the crime is too short to prevent a local destruction of the outer wall of the building, the forced entry of the terrorists into the building, their actual destructive work in the interior of the building and their escape. In addition, there is often no possibility of erecting a protective wall at a considerable distance from the facade wall of the building owing to the lack of space at the locality. Sufficient security for the prevention of logistically carefully prepared acts of terror is thus in most cases not provided for at all.